There are known apparatuses such as dispensers in which an image processing section is mounted to perform coating work while carrying out position correction of work, and/or microscopes for detecting, in an enlarged manner, the distribution state of a group of compounds existing, in the spot state, in a sample to be analyzed, etc.
In these apparatuses, when coating fluid sample onto the work surface, sample and it is required to precisely control the distance between the front end part of the probe and the work surface.
A sample collecting system described in the Patent reference 1 aims at obtaining a sample from at least a point of the surface array for the purpose of subsequent analysis, and uses an image analysis technique for controlling a distance between a probe and the surface array.
The sample collecting system comprises a light source, a camera and an image processing section. The light source is disposed at the front end part of the probe in a manner adjacent thereto and serves to irradiate lights toward the front end part of the probe so that shadow of the front end part of the probe falls onto the surface array. The camera is provided for the purpose of acquiring an image of the front end part of the probe and an image of a shadow appearing on the surface array obtained by irradiating lights from the light source toward the probe. The image processing section applies the average line brightness (LAB) to an image picked up by the camera to determine an actual distance between the front end of the probe and the surface array.
Namely, in the sample collecting system, the light source irradiates lights toward the probe, and the camera serves to take thereto successive images of the front end part of the probe and the surface array, more specifically, a shadow of the front end part of the probe fallen on the surface array. Further, the image processing section make the image of the shadow into binary score. At this time, since the LAB indicating the front end part of the probe and the surface array has the lowest brightness, the image processing section measures, as a distance between the front end part of the probe and the surface array, a distance between two horizontal lines which are the lowest LAB.
For the purpose keeping constant a distance between a sample plate and the front end part of a probe in dropping droplet onto a sample plate, an image dividing apparatus described in the Patent reference 2 comprises, at the side part of the probe, a proximity sensor for measuring a distance between the probe and the sample plate. The sample plate is moved in upper and lower directions and in a horizontal direction with it being mounted on a stage. The stage is connected to a control section and the control section controls movement of the stage. The control section performs feedback control of the stage so that a measured value of the proximity sensor becomes equal to a set value to upwardly move the sample plate in dropping droplet from the probe to allow the distance between the probe and the sample plate to be close to each other to allow the droplet to come into contact with the sample plate to perform image division.